Clinical and Molecular Studies in Families with Congenital or Hereditary Cataracts This study will explore the clinical and hereditary (genetic) features of inherited cataracts. A cataract is a clouding of the eye lens, which focuses light on the back of the eye. When the lens becomes cloudy and does not let light through, vision is impaired. Cataracts may be associated with vision problems alone, or with other problems, such as changes in facial appearance or skin problems. A better understanding of these genetic conditions may help in the development of better diagnostic tests.